335D Wagner Aftermarket Intercooler / Downpipe

I'm looking to understand how best to get the most out of my 335D.



Planning to at some stage get a custom remap and DPF delete as well sorting out the Egr delete.



I'm also interested in an aftermarket Intercooler and a Twin Turbo Diesel Downpipe... Wagner seem quite popular...



Intercooler

http://ift.tt/1nMjLdh



Downpipe

http://ift.tt/1nMjLdm



Can someone tell me if the DPs are catless? In the link it does say 'less back pressure' but can't tell if they're catless:mad0259: .. Also, whther or not they are restrictive?



Does anyone have any experience with these or know what sort of gains they will have?



Thanks.